The invention relates to an arrangement for limiting the axial play of a number of gears of a watch drive mechanism and also of the time adjustment shaft of the watch.
The various gears of the indicating mechanism of a small watch are rotatably supported on studs or shafts immovably mounted on a mounting plate on which the gears are also axially movable. Also, the time adjustment shaft of a small watch is axially movably supported by a slide bearing. Axial play of the gears of the indicating mechanism is limited at the side of the support plate by means of stops provided on the support plate, which stops are engaged by a sleeve or a rim associated with the gear. In opposite direction, axial play of the gears is limited in accordance with prior art arrangements by mounting a bridge member on the support plate which bridge member is abutted also by a sleeve or a rim associated with the gear. Also known is the provision of a bridge plate which is screwed onto the support plate and provides a stop structure for a number of gears of the indicating mechanism, that is, a structure which combines the functions of a number of bridge members. The axial play of the adjustment shaft on the other hand is generally limited by way of a spring arm which projects into a groove associated with the adjustment shaft.
The bridge members as well as an appropriate bridge plate and also the spring arm projecting into the adjustment shaft groove need to be manufactured and mounted onto the support plate with high accuracy. This requires not only a relatively high manufacturing effort but also results in relatively difficult and tedious assembly steps which, generally, cannot be performed by automatic manufacturing equipment. As a result of such tedious assembly and the impossibility to perform the assembly automatically, assembly of such small watches is relatively expensive.
It is therefore the object of the present invention to provide an arrangement for limiting the axial play of certain gears and shafts of a watch time indicating mechanism which is relatively simple to manufacture and with which assembly of the watch is facilitated to such a degree that assembly by means of automatic manufacturing equipment is possible.